This application is based on Japanese Patent Application No. 2000-229281 filed Jul. 28, 2000,the contents of which are incorporated hereinto by reference.
1. Field of the Invention
The present invention relates in general to a hydraulic pressure control apparatus, and more particularly to techniques for determining a control value of a pressure control actuator provided in the pressure control apparatus.
2. Discussion of Related Art
JP-A-8-67242 discloses a hydraulic pressure control apparatus including (a) a hydraulic pressure source device provided with a pressure control actuator operable according to a control value, and (b) an actuator control device which includes a control-value determining portion operable to determine the control value of the pressure control actuator, and which controls the pressure control actuator according to the control value determined by the control-value determining portion. In this hydraulic pressure control apparatus, the control value of the pressure control actuator is determined on the basis of an operating force applied to a manually operable brake operating member. Accordingly, an output hydraulic pressure of the hydraulic pressure control apparatus changes immediately in response to a change in the operating force of the brake operating member. Although the hydraulic pressure control apparatus has a high degree of control response, it tends to suffer from control hunting.
It is therefore an object of the present invention to provide a hydraulic pressure control apparatus which has a reduced degree of control hunting, while avoiding deterioration of the control response.
The above object may be achieved according to any one of the following modes of the present invention, each of which is numbered like the appended claims and depends from the other mode or modes, where appropriate, to indicate and clarify possible combinations of elements or technical features. It is to be understood that the present invention is not limited to the technical features or any combinations thereof which will be described for illustrative purpose only. It is to be further understood that a plurality of elements or features included in any one of the following modes of the invention are not necessarily provided all together, and that the invention may be embodied without some of the elements or features described with respect to the same mode.
(1) A hydraulic pressure control apparatus for use with a manually operable operating member, the hydraulic pressure control apparatus comprising:
a hydraulic pressure source device including a pressure control actuator operable according to a control amount, the hydraulic pressure source device being operable to generate an output pressure thereof on the basis of a fluid pressure corresponding to an operating force of the manually operable operating member, and on the basis of a control pressure controlled by the pressure control actuator; and
an actuator control device including a final-control-value determining portion operable to determine a final value of the control amount, the actuator control device controlling the pressure control actuator according to the final value determined by the final-control-value determining portion,
and wherein the final-control-value determining portion determines the final value of the control amount on the basis of at least two provisional control values selected from the group consisting of (a) at least one first provisional control value each of which is determined on the basis of at least one physical quantity including at least one of (i) an operating-state value representative of an operating state of the manually operable operating member and (ii) the output pressure of the hydraulic pressure source device, and (b) at least one second provisional control value each of which is determined on the basis of a combination of physical quantities which includes at least two of the operating-state value, the output pressure and the control pressure controlled by the pressure control actuator.
In the hydraulic pressure control apparatus constructed according to the above mode (1) of the present invention, the hydraulic pressure source device is operated to generate its output pressure on the basis of the fluid pressure corresponding to the operating force of the manually operable operating member, and the control pressure which is controlled by the pressure control actuator according to the control amount controlled by the actuator control device. The actuator control device is arranged to control the pressure control actuator, according to a predetermined rule, that is, so as to establish a predetermined relationship among the operating force or other operating-state value of the operating member, the control pressure controlled by the pressure control actuator and the output pressure of the hydraulic pressure source device. Therefore, when the two of these three physical quantities are determined, the remaining physical quantity can be determined on the basis of the determined two physical quantities and according to the predetermined relationship. Similarly, when one of the three physical quantities is determined, the remaining two physical quantities can be determined on the basis of the determined one physical quantity and according to the predetermined relationship.
In the present hydraulic pressure control apparatus, the final-control-value determining portion of the actuator control device is arranged to determine the final value of the control amount of the pressure control actuator, on the basis of at least two provisional control values selected from the group consisting of (a) at least one first provisional control value each determined on the basis of at least one physical quantity including at least one of the operating-state value of the manually operable operating member and the output pressure of the hydraulic pressure source device, and (b) at least one second provisional control amount each determined on the basis of two or three of the operating-state value, the output pressure and the control pressure controlled by the pressure control actuator. One of the three physical quantities which have the predetermined relationship as described above is the operating-state value representative of the operating state of the manually operable operating member. The operating-state value used to determine the final value of the control amount for controlling the pressure control actuator may include not only the operating force to be applied to the operating member, but also the operating stroke or amount of the operating member, and may consist of a combination of the operating force and stroke of the operating member when it is operated. Where the hydraulic pressure control device is used for a braking system for an automotive vehicle and includes a brake operating member as the manually operable operating member, at least one of the operating force and stroke of the operating member represents a braking force to be generated by the braking system, which braking force is desired by the vehicle operator.
For instance, a desired value of the control pressure can be determined on the basis of one of the operating-state value and the output pressure and according to the predetermined rule or relationship, so that the control amount for controlling the pressure control actuator to control the actual value of the control pressure can be determined on the basis of the determined desired value of the control amount.
The operating-state value of the operating member can be estimated on the basis of the output pressure of the hydraulic pressure source device and the control pressure controlled by the pressure control actuator. Therefore, the desired value of the control pressure can be determined on the estimated operating-state value, so that the control amount can be determined. Similarly, the output pressure can be estimated on the basis of the operating-state value and the control pressure, so that the control amount can be determined.
Further, the control amount can be determined on the basis of the operating-state value and the output pressure, and the control amount can be determined on the basis of all of the three physical quantities consisting of the operating-state value, the control pressure and the output pressure. Where the control amount is determined on the basis of the operating-state value and the output pressure, the control amount may be determined, for instance, on the basis of a control error of the actual value of the output pressure with respect to a desired value which is determined on the basis of the operating-state value and according to the predetermined rule or relationship.
The at least two provisional control values used by the final-control-value determining portion of the actuator control device to determine the final value of the control amount for the pressure control actuator may be selected from among the following six provisional control amounts:
1) a first provisional control amount determined on the basis of the operating-state value of the manually operable operating member;
2) a second provisional control amount determined on the basis of the output pressure of the hydraulic pressure source device and the control pressure controlled by the pressure control actuator;
3) a third provisional control amount determined on the basis of the output pressure;
4) a fourth provisional control amount determined on the basis of the output pressure and the stating-state value;
5) a fifth provisional control amount determined on the basis of the operating-state value and the control pressure; and
6) a sixth provisional control amount determined on the basis of the operating-state value, the control pressure and the output pressure.
In the above case, the final value of the control amount for controlling the pressure control actuator is determined by the final-control-value determining portion of the actuator control device, on the basis of the at least two provisional control values selected from among the above-indicated six provisional control amounts.
For instance, the final value of the control amount is determined on the basis of the first and third provisional control amounts. Where the pressure control actuator is controlled according to the final value of the control amount determined on the basis of the first provisional control amount, the pressure control actuator is relatively likely to suffer from a comparatively high degree of control hunting, while the control response is relatively high. Where the pressure control actuator is controlled according to the final value determined on the basis of the third provisional control amount, the pressure control actuator tends to suffer from a relatively low degree of control response, while the control hunting is less likely to be encountered. Where the pressure control actuator is controlled according to the final value of the control amount determined on the basis of the first and third provisional control amounts, the control hunting can be reduced, while reducing the deterioration of the control response.
(2) A hydraulic pressure control apparatus according to the above mode (1), wherein the hydraulic pressure source device includes:
a power-operated pressure source device electrically operable to pressurize a working fluid; and
a master cylinder including a housing, and a pressurizing piston fluid-tightly and slidably received in the housing and cooperating with the housing to define a front pressurizing chamber on one of opposite sides thereof and a rear pressurizing chamber on the other side thereof, the pressurizing piston being advanced by the operating force of the manually operable operating member by an operator of the apparatus, to pressurize the working fluid in the front pressurizing chamber,
and wherein the pressure control actuator is arranged to control a pressure of the working fluid in the rear pressurizing chamber, as the above-indicated control pressure.
In the hydraulic pressure control apparatus according to the above mode (2), the pressurizing piston receives the operating force of the operating member and a boosting or assisting force based on the control pressure in the rear pressurizing chamber of the master cylinder, so that the pressurizing piston is advanced by a sum of these forces. The advancing movement of the pressurizing piston causes the working fluid in the front pressurizing chamber to be pressurized to a pressure which is a sum of the fluid pressure corresponding to the operating force of the operating member and the control pressure controlled by the pressure control actuator. The thus generated fluid pressure in the front pressurizing chamber is the output pressure of the hydraulic pressure source device.
The power-operated pressure source device may include a pump device including a pump and an electric motor for driving the pump.
The pressure control actuator may be provided by the power-operated pressure source device. In this case, the output pressure of the power-operated pressure source device can be controlled to control the control pressure in the rear pressurizing chamber of the master cylinder, by controlling the amount of electric energy to be supplied from a driver circuit to the electric motor of the power-operated pressure source device. Alternatively, the pressure control actuator may include an electromagnetically operated pressure control valve operable to control the output pressure of the power-operated pressure source device to be applied to the pressurizing chamber. In this case, the control pressure in the rear pressurizing chamber can be controlled by the electromagnetically operated pressure control valve. The pressure control valve may be a linear control valve operable to control a pressure difference across the pressure control valve, according to an amount of electric current applied thereto. Alternatively, the pressure control valve may be a shut-off valve whose duty ratio is controllable by periodic application of an electric current thereto. Where the pressure control valve of the pressure control actuator is a linear control valve, the amount of electric current applied to the linear control valve is the control amount indicated above. Where the pressure control valve is a shut-off valve, the duty ratio, ON time or OFF time of the shut-off valve is the control amount.
The control amount of the pressure control actuator determines the fluid pressure in the rear pressurizing chamber, namely, the control pressure, which in turn determines the boosting force to be applied to the pressurizing piston of the master cylinder, in addition to the input force in the form of the operating force of the manually operable operating member. Thus, the input force is boosted by the boosting force into the output force of the master cylinder (hydraulic pressure source device). The control amount of the pressure control actuator is desirably determined such that the boosting ratio (servo ratio) which is a ratio of the output force to the input force is controlled to a predetermined value. However, the control amount may be determined otherwise. Regarding the input force of the pressurizing piston, it is noted that where a booster is provided between the master cylinder and the operating member, the input force to be applied to the pressurizing piston is the output force of the booster, which corresponds to the operating force of the operating member.
(3) A hydraulic pressure control apparatus according to the above mode (1) or (2), wherein the hydraulic pressure source device includes a master cylinder operable to generate a fluid pressure corresponding to the operating force of the manually operable operating member, and a pressure-increasing device disposed downstream of the master cylinder and operable to increase the fluid pressure generated by the master cylinder, the pressure-increasing device including the pressure control actuator.
(4) A hydraulic pressure control apparatus according to the above mode (3), wherein the pressure-increasing device includes a pump disposed downstream of the master cylinder, and an electric motor operable to drive the pump.
In the hydraulic pressure control apparatus according to the above mode (4), the pressure-increasing device functions as the pressure control actuator. For example, the amount of increase of the output pressure of the master cylinder by the pressure-increasing device can be controlled by controlling the amount of electric energy to be supplied from a driver circuit to the electric motor.
Where the pressure-increasing device includes a pressure control valve operable to control the delivery pressure of the pump, this pressure control valve functions as the pressure control actuator. In this case, the pressure of the pressurized fluid delivered from the pump is controlled to be higher than the pressure of the fluid pressurized by the master cylinder, by controlling the pressure control valve. The pressure control valve may be disposed in parallel with the pump, or in series with the pump. Where the pressure control valve is disposed in parallel with the pump, the pressure control valve may be disposed between the pump and a low-pressure source, or between the pump and the master cylinder. The pressure control valve may be either a linear control valve arranged to control a pressure difference across the valve, according to an amount of electric current applied thereto, or an electromagnetically operated shut-off valve whose duty ratio is controlled, as described above with respect to the pressure control valve in the apparatus according to the above mode (2).
(5) A hydraulic pressure control apparatus according to any one of the above modes (1)-(4), wherein the final-control-value determining portion of the actuator control device includes a portion operable to determine the final value of the control amount on the basis of the at least two provisional control values and weights of the at least two provisional control values.
In the hydraulic pressure control apparatus according to the above mode (5) wherein the final value of the control amount for the pressure control actuator is determined on the basis of not only the at least two provisional control values but also the weights given to those provisional control values, so that the pressure control actuator can be controlled with an adequate compromise between the control response and the freedom from the control hunting. For instance, the control response can be improved by increasing the weight to be given to the first provisional control amount indicated above, while the control hunting can be reduced by increasing the weight to be given to the second or third provisional control amount indicated above.
The weights are ratios by which the respective provisional control values are multiplied and whose sum is equal to 1. That is, the weights are relative values of importance of the provisional control values used to determine the final value. The weight of each provisional control value may be 0 or 1.
(6) A hydraulic pressure control apparatus according to the above mode (5), wherein the portion of the final-control-value determining portion includes a weight determining portion operable to determine the weight to be given to the provisional control value determined on the basis of the operating-state value of the manually operable operating member, such that the provisional control value determined on the basis of the operating-state value is larger when a rate of change of the operating-state value is higher than a predetermined threshold, than when the rate of change is not higher than the predetermined threshold.
For instance, the weight to be given to the provisional control value determined on the basis of the operating-state value of the operating member is increased when the operating speed of the operating member is higher than a predetermined threshold. When the operating speed is relatively high, the pressure control actuator is required to be controlled with a relatively high degree of control response to the operation of the operating member. The weight may be changed in steps or continuously as the rate of change of the operating-state value of the operating member is changed. The weight may be set to be 1.
The weight of the provisional control value determined on the basis of the operating-state value of the operating member may be set to be 1 when the rate of change of the operating-state value is higher than the predetermined threshold and when the operating-state value is larger than a predetermined threshold.
(7) A hydraulic pressure control apparatus according to any one of the above modes (1)-(6), further comprising:
an operating-state value detecting device operable to detect the operating-state value of the manually operable operating member;
a control-pressure detecting device operable to detect the control pressure controlled by the pressure control actuator; and
an output-pressure detecting device operable to detect the output pressure of the hydraulic pressure source device,
and wherein the final-control-value determining portion includes a provisional-control-value determining portion operable to determine the at least one first provisional control value on the basis of at least one of an output signal of the operating-state-value detecting device and an output signal of the output-pressure detecting device, and determine the at least one second provisional control value on the basis of the output signals of at least two of the operating-state-value detecting device, the control-pressure detecting device and the output-pressure detecting device,
the actuator control device further including a defective-device determining portion operable on the basis of at least three provisional control values selected from among the at least one first provisional control value and the at least one second provisional control value which are determined by the provisional-control-value determining portion, the defective-device determining portion determining which one of the operating-state-value detecting device, the control-pressure detecting device and the output-pressure detecting device is defective.
All provisional control values determined on the basis of at least one of the output signals of the three detecting devices indicated above are theoretically substantially equal to each other while these detecting devices are all normally functioning. By comparing the at least three provisional control values, therefore, it is possible to detect a defective one of the detecting devices. Where the sensor diagnosing portion is operated on the basis of three provisional control values, and where one of the three detecting devices is defective, this detective detecting device can be detected, if the two of the three provisional control values are determined on the basis of the two physical quantities and are substantially equal to each other, while the remaining provisional control value is determined on the basis of the physical quantity different from the physical quantities used to determine the above-indicated two provisional control values. This limitation does not apply to the defective-device determining portion when it is operable on the basis of at least four provisional control values, the above-indicated limitation does not
(8) A hydraulic pressure control apparatus according to the above mode (7), wherein the actuator control device includes a special final-control-value determining portion operable when at least one of the operating-state-value detecting device, the control-pressure detecting device and the output-pressure detecting device is diagnosed to be defective by the defective-device determining portion, the special final-control-value determining portion determining the final value of the control amount, on the basis of the at least two provisional control values except at least one provisional control value which is determined on the basis of the output signal of the at least one detecting device which has been diagnosed to be defective.
In the hydraulic pressure control apparatus according to the above mode (8), the pressure control actuator can be controlled even after at least one of the detecting devices is defective.
(9) A hydraulic pressure control apparatus according to the above mode (8), wherein the special final-control-value determining portion is operable to substantially zero a weight which is given to each of the at least one provisional control value which is determined on the basis of the output signal of the at least one detecting device which has been diagnosed to be defective by the defective-device determining portion.
In the apparatus according to the above mode (9) wherein the weight to be given to each provisional control value determined on the basis of the output signal of each defective detecting device is zeroed or set to be extremely small, the final value of the control amount is determined without taking into account each provisional control value determined on the basis of the output signal of each defective detecting device. Thus, the determination of the final value when at least one of the detecting devices is found defective can be effected according to the same formula as used when the detecting devices are all normal, such that the weights to be given to the individual provisional control values are suitably set depending upon whether any of the detecting devices is defective or not.
(10) A hydraulic pressure control apparatus according to any one of the above modes (1)-(9), wherein the final-control-value determining portion is operable to determine the final value of the control amount on the basis of at least two of a first provisional control amount determined on the basis of the operating-state value of the manually operable operating member, a second provisional control amount determined on the basis of the output pressure of the hydraulic pressure source device and the control pressure controlled by the pressure control actuator, and a third provisional control amount determined on the basis of the output pressure of the hydraulic pressure source device.
In the hydraulic pressure control apparatus according to the above mode (10), the final-control-value determining portion of the actuator control device is arranged to determine the final value of the control amount of the pressure control actuator on the basis of at least two provisional control values selected from among the first, second and third provisional control amounts.
However, the final-control-value determining portion may be arranged to determine the final value of the control amount on the basis of at least two provisional control values selected from among the above-indicated first and third provisional control amounts and a fourth provisional control amount determined on the basis of the operating-state value of the operating member and the output pressure of the hydraulic pressure source device.
(11) A hydraulic pressure control apparatus according to the above mode (10), wherein the final-control-value determining portion is operable to determine said final value of said control amount on the basis of said first, second and third provisional control amounts.
In the hydraulic pressure control apparatus according to the above mode (11), the final value of the control amount for the pressure control actuator is determined on the basis of the first, second and third provisional control amounts. However, the final value may be determined on the basis of the above-indicated first and third provisional control amounts and a fourth provisional control amount determined on the basis of the operating-state value of the operating member and the output pressure of the hydraulic pressure source device.
(12) A hydraulic pressure control apparatus according to the above mode (10) or (11), wherein the actuator control device includes:
a first provisional-control-amount determining portion operable to determine the first provisional control amount on the basis of an output signal of an operating-state-value detecting device operable to detect the operating-state value of the manually operable operating member;
a second provisional-control-amount determining portion operable to determine the second provisional control amount on the basis of an output signal of a control-pressure detecting device operable to detect the control pressure controlled by the pressure control actuator, and an output signal of an output-pressure detecting device operable to detect the output pressure of the hydraulic pressure source device;
a third provisional-control-amount determining portion operable to determine the third provisional control amount on the basis of the output signal of the output-pressure detecting device; and
a sensor diagnosing portion operable to compare the first, second and third provisional control amounts, and thereby determine whether any one of the operating-state-value detecting device, the control-pressure detecting device and the output-pressure detecting device is defective.
By comparing the determined first, second and third provisional control amounts, it is possible to determine whether any one of the operating-state-value detecting device, control-pressure detecting device and output-pressure detecting device is defective.
For instance, it is possible to determine that all of the three detecting devices are normal, if a difference between the maximum and minimum ones of the first, second and third provisional control amounts is smaller than a predetermined threshold, and that any one of the three detecting devices is defective, if the above-indicated difference is not smaller than the threshold.
(13) A hydraulic pressure control apparatus according to the above mode (10) or (11), wherein the actuator control device includes:
a first provisional-control-amount determining portion operable to determine the first provisional control amount on the basis of an output signal of an operating-state-value detecting device operable to detect the operating-state value of the manually operable operating member;
a second provisional-control-amount determining portion operable to determine the second provisional control amount on the basis of an output signal of a control-pressure detecting device operable to detect the control pressure controlled by the pressure control actuator, and an output signal of an output-pressure detecting device operable to detect the output pressure of the hydraulic pressure source device;
a third provisional-control-amount determining portion operable to determine the third provisional control amount on the basis of the output signal of the output-pressure detecting device; and
a defective-device determining portion operable on the basis of the first, second and third provisional control amounts, to determine which one of the operating-state-value detecting device, the control-pressure detecting device and the output-pressure detecting device is defective.
In the hydraulic pressure control apparatus according to the above mode (13), the first, second and third provisional control amounts are compared with each other, to determine which one of the three detecting devices is defective.
Where the second and third provisional control amounts are substantially equal to each other while the first provisional control amount is considerably different from the second and third provisional control amounts, for instance, it is possible to determine that the operating-state-value detecting device is defective, as described in detail in the DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS. Where the first and third provisional control amounts are substantially equal to each other while the second provisional control amount is considerably different from the first and third provisional control amounts, it is possible to determine that the control-pressure detecting device is defective. In the other cases where the difference between the maximum and minimum ones of the three provisional control amounts is larger than a predetermined threshold, it is possible to determine that the output-pressure detecting device is defective.
(14) A hydraulic pressure control apparatus according to the above mode (13), wherein the actuator control device includes a special final-control-value determining portion operable, to determine the final value of the control amount for the pressure control actuator, on the basis of the first, second and third provisional control amounts except the provisional control amount which is determined on the basis of the output signal of the detecting device which has been diagnosed to be defective by the defective-device determining portion.
(15) A hydraulic pressure control apparatus according to the above mode (13) or (14), wherein the special final-control-value determining portion is operable to substantially zero a weight which is given to each of the provisional control amount which is determined on the basis of the output signal of the detecting device which has been diagnosed to be defective by the defective-device determining portion.
(16) A hydraulic pressure control apparatus according to any one of the above modes (1)-(15), wherein the actuator control device comprises:
a control-pressure detecting device operable to detect the control pressure controlled by the pressure control actuator; and
a feedback control portion operable to feedback-control the pressure control actuator such that the control pressure as detected by the control-pressure detecting device coincides with a desired value corresponding to the final value of the control amount determined by the final-control-value determining portion.
(17) A hydraulic pressure control apparatus according to any one of the above modes (1)-(15), wherein the actuator control device comprises:
an output-pressure detecting device operable to detect the output pressure of the hydraulic pressure source device;
an operating-state-value detecting device operable to detect the operating-state value of the manually operable operating member;
a control-pressure estimating portion operable to estimate the control pressure controlled by the pressure control actuator, on the basis of the output pressure detected by the output-pressure detecting device and the operating-state value detected by the operating-state-value detecting device; and
a feedback control portion operable to feedback-control the pressure control actuator such that the control pressure as estimated by the control-pressure estimating portion coincides with a desired value corresponding to the final value of the control amount determined by the final-control-value determining portion.
In the hydraulic pressure control apparatus according to the above mode (17) wherein the pressure control actuator is feedback-controlled on the basis of the estimated control pressure, the control hunting can be made smaller than in the apparatus according to the above mode (16) wherein the pressure control actuator is feedback-controlled on the basis of the detected control pressure.
(18) A hydraulic pressure control apparatus according to any one of the above modes (1)-(15), wherein the pressure control actuator includes a pressure control valve operable to control the control pressure according to an amount of electric current applied thereto as the control amount, and the actuator control device includes:
a current detecting device operable to detect an amount of electric current actually flowing through the pressure control valve; and
a feedback control portion operable to feedback-control the pressure control actuator such that the amount of electric current as detected by the current detecting device coincides with a desired value corresponding to the final value of the control amount determined by the final-control-value determining portion.
(19) A hydraulic pressure control apparatus for use with a manually operable operating member, the hydraulic pressure control apparatus comprising:
a hydraulic pressure source device including a pressure control actuator operable according to a control amount, the hydraulic pressure source device being operable to generate an output pressure thereof on the basis of a fluid pressure corresponding to an operating force of the manually operable operating member, and on the basis of a control pressure controlled by the pressure control actuator;
an operating-state-value detecting device operable to detect an operating-state value representative of an operating state of the manually operable operating member;
an output-pressure detecting device operable to detect the output pressure of the hydraulic pressure source device;
a control-pressure estimating device operable to estimate the control pressure controlled by the pressure control actuator, on the basis of the operating-state value detected by the operating-state-value detecting device and the output pressure detected by the output-pressure detecting device; and
an actuator control device including a final-control value determining portion operable to determine a final value of the control amount, the actuator control device feedback-controlling the pressure control actuator such that the control pressure as estimated by the control-pressure estimating device coincides with a desired value corresponding to the final value of the control amount determined by the final-control-value determining portion,
and wherein the final-control-value determining portion determines the final value of the control amount on the basis of at least one provisional control values selected from the group consisting of (a) at least one first provisional control value each of which is determined on the basis of at least one physical quantity including at least one of (i) an operating-state value representative of an operating state of the manually operable operating member and (ii) the output pressure of the hydraulic pressure source device, and (b) at least one second provisional control value each of which is determined on the basis of a combination of physical quantities which includes at least two of the operating-state value, the output pressure and the control pressure controlled by the pressure control actuator.
The hydraulic pressure control apparatus according to the above mode (19) may incorporate any of the technical features of the above modes (1)-(18).
(20) A hydraulic pressure control apparatus for use with a manually operable operating member, the hydraulic pressure control apparatus comprising:
a hydraulic pressure source device including a pressure control actuator operable according to a control amount, the hydraulic pressure source device being operable to generate an output pressure thereof on the basis of a fluid pressure corresponding to an operating force of the manually operable operating member, and on the basis of a control pressure controlled by the pressure control actuator; and
an actuator control device including a control-amount determining portion operable to determine the control amount on the basis of at least two of (a) an operating-state value representative of an operating state of the manually operable operating member, (b) the output pressure of the hydraulic pressure source device, and (c) the control pressure controlled by the pressure control actuator, the actuator control device controlling the pressure control actuator according to the control amount determined by the control-amount determining portion.
The hydraulic pressure control apparatus according to the above mode (20) may incorporate any of the technical features of the above modes (1)-(19).